No matter what he did or how much he tweeted during his first four months in office, President Donald Trump has mostly held on to the loyalty of congressional Republicans — even those who might have the most to lose at the ballot box next year.

But that deference to the White House has begun to erode, slowly and unevenly, over the past week, with one vulnerable Republican congressman even dropping the word “impeachment” on national television.

The events of the past nine days — including the firing of FBI Director James B. Comey, reports that Trump revealed classified information to Russian officials, and reports that Trump asked Comey to stop investigating his former national security adviser’s contacts with the Kremlin — have rocked Capitol Hill.

Some of the pressure on GOP lawmakers to weigh in on an ongoing investigation into possible ties between the Trump campaign and Russian operatives was relieved Wednesday evening when the Justice Department appointed former FBI Director Robert Mueller as a special counsel to oversee the probe.

New York GOP Rep. Chris Collins, the first member of Congress to endorse Trump, said the pressure was off House Republicans to answer questions about the need for a special counsel.

“The one positive development would be that we don’t have to answer that question anymore,” said Collins, a 2018 Democratic target.

And some Republicans, including Florida Rep. Brian Mast, who weren’t calling for a special counsel before, are now suddenly on board.

“I don't know that much about him but it will be good to see what plays out with the special investigation,” Mast said. But when pressed whether a special counsel was something that he’d been supportive of before, Mast dodged.

“I always call for transparency. I always say we should be transparency hawks,” he said.

The recent turmoil still had some vulnerable Republicans sharply criticizing the administration. Others wanted to wait and see if recent media reports were true before commenting — but they may not have to wait very long.

Sen. Jeff Flake, a frequent Trump critic, refused to criticize his fellow Republicans for not being as vocal as he is. But, the Arizona Republican said, if the reports prove true, “Republicans shouldn’t be OK with that.”

Democrats are waiting to see whether the past week inspires a breaking point among Republicans who have generally stood by the White House. Delaware Sen. Chris Coons said he still had not seen many Republicans publicly weighing in on the controversies, but they would likely face a “moment of decision” by the end of next week.

Coons pointed out that Deputy Attorney General Rod Rosenstein will brief all senators on Thursday on Comey’s firing. The Delaware lawmaker also expects Congress to quickly gain access to any transcripts, memos or tapes of conversations pertaining to recent events.

“Many Republicans today are calling for Comey to testify, the memos or transcripts or recordings to be given to Congress. That’s not an unreasonable position,” Coons said. “But once we have all of that, if it confirms the stories and reports to date, to, at that point, fail to act would be grossly irresponsible.”

Some speak out

The past week’s events have already caused several vulnerable Republicans, especially those in districts carried by Hillary Clinton last fall, to speak out more forcefully against the Trump White House.

The most significant comments came from Florida Rep. Carlos Curbelo, who dropped the I-word on TV on Tuesday. In fact, his spokeswoman has tried to correct the record with reporters who have been identifying Michigan Rep. Justin Amash, a Freedom Caucus member, as the only Republican to have mentioned impeachment.

“Congressman Curbelo was actually the first to mention impeachment,” the spokeswoman emailed reporters Wednesday.

Clinton carried Curbelo’s 26th District handily, and especially after his recent vote for the GOP leadership’s health care legislation, Democrats are eager to take him out in 2018.

Another top Democratic target, Virginia Rep. Barbara Comstock, is often cautious about weighing in. But she’s been more outspoken of late. She released a strongly worded statement Tuesday after reports that Trump had shared classified information with Russian officials in which she referred to “inexplicable stories coming from the White House.”

In a statement in which she said she could not defend Comey’s firing last week, Comstock called for an “independent investigation that the American people can trust.”

Comstock represents a northern Virginia swing district that Clinton carried by 10 points and is home to many federal workers. That sometimes requires her to buck her party (most recently, on the health care vote).

But Democrats immediately criticized her for not doing enough.

“Barbara Comstock needs to do more than issue vague statements indicating she is troubled by the stories coming out of the White House,” said state Sen. Jennifer Wexton, who’s challenging Comstock in the 10th District. Wexton called on Comstock to sign the Democrats’ discharge petition to force a vote on creating an independent commission.

Other vulnerable Republicans have gone further, getting more specific in their calls for an independent investigation.

Prior to the Mueller announcement, Rep. Steve Knight, for example, on Tuesday called for a special prosecutor to take over the FBI investigation. The two-term member sits in a southern California district that Clinton won by nearly 7 points.

Nevada Sen. Dean Heller, the most vulnerable GOP senator up for re-election next year, has said over the past week that a independent prosecutor should be on the table if committees in the House and Senate “cannot get to answers.”

Other Republicans in Clinton districts, like Reps. Darrell Issa of California and Erik Paulsen of Minnesota, have called for an independent investigation in the wake of Comey’s firing, but have been less clear about what form it should take.

After finding out about the Justice Department decision Wednesday, Minnesota Rep. Jason Lewis said that “if DOJ thought that was the proper thing to do, then let DOJ do it.”

But he also expressed some hesitation over multiple ongoing investigations, including in both the House and Senate, and the FBI.

“We all want the truth to come out, we all want to go where the facts lead, but I hope we don’t get into a situation of ‘It’s never good enough’ and this thing just drags and drags and politics gets in the way,” Lewis said. “Anything that gets the politics out of it, I’m in favor of.”

Waiting on facts

Other Republican members in tight races were still waiting to weigh in on whether a special counsel or independent commission should lead the investigations, ahead of Wednesday evening’s announcement.

These GOP lawmakers have to strike a delicate balance between courting Trump voters, and combating Democratic criticism for not standing up to the administration.

Rep. Will Hurd said he supported the Oversight and Government Reform Committee’s push to obtain Comey’s memos and testimony. The Texas Republican said the committee’s actions are “important first steps to determine whether a special prosecutor is necessary.” Inside Elections with Nathan L. Gonzales rates his race a Tossup.

Rep. John Katko similarly said he needed more information before making a decision about a special counsel or independent commission.

“I think you follow the facts and let the facts dictate the decision,” the New York Republican said Tuesday. “You can’t make a decision based on emotions. It’s got to be based on facts.”

Katko’s race is rated Likely Republican, and he is one of the Democratic Congressional Campaign Committee’s targets in 2018. Clinton carried his district by 4 points.

“Who knows what to believe,” Katko said. “This president has been under attack by the media. And it’s imperative, now more than ever, to make decisions based on the facts and nothing else.”

A 2018 distraction?

Even as Republicans continue to face questions about the latest news, House Speaker Paul D. Ryan suggested he was not concerned about how the Russian investigations would affect members up for re-election.

“I don’t worry about things that are outside of my control,” the Wisconsin Republican said when asked at a Wednesday morning press conference about the political effect.

“We’re going to keep advancing our reforms that we were elected to advance while we do all these other things that are within our responsibility,” the speaker said. “And that’s what we’ll be judged in 2018.”

But some GOP lawmakers are beginning to express fear that the daily drips of news on the Russian investigations slow the legislative agenda they hope to highlight in the midterms.

Florida Rep. Mario Diaz-Balart told reporters that he wanted thorough investigations, but they needed to proceed quickly. Diaz-Balart’s race is rated Solid Republican, but he is also a DCCC target, with Trump having carried his district by less than 2 points.

“Clearly what could be [considered] now as just a distraction, could be an impediment to getting things done,” he said.